Re: [PATCH v4 6/8] firmware: qcom: scm: add modparam to control QSEECOM enablement

From: Dmitry Baryshkov
Date: Thu Jun 26 2025 - 07:08:56 EST


On Thu, Jun 26, 2025 at 12:11:20PM +0200, Johan Hovold wrote:
> On Wed, Jun 25, 2025 at 01:53:25AM +0300, Dmitry Baryshkov wrote:
> > From: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> >
> > In preparation to enabling QSEECOM for the platforms rather than
> > individual machines provide a mechanism for the user to override default
> > selection. Allow users to use qcom_scm.qseecom modparam.
> >
> > Setting it to 'force' will enable QSEECOM even if it disabled or not
> > handled by the allowlist.
> >
> > Setting it to 'off' will forcibly disable the QSEECOM interface,
> > allowing incompatible machines to function.
> >
> > Setting it to 'roefivars' will enable the QSEECOM interface, making UEFI
> > variables read-only.
> >
> > All other values mean 'auto', trusting the allowlist in the module.
>
> I don't see the need for this. The kernel should just provide sensible
> defaults.

It does provide _defaults_. However with the next commit we mass-enable
QSEECOM for SoC families, which includes untested WoA devices. If the
user observes a misbehaviour of the UEFI vars or any other
QSEECOM-related driver on those platforms, it is much easier to let
users test and workaround UEFI misbehaviour.

I can probably add an explicit message that if the modparam is used, it
must be reported to linux-arm-msm@.

>
> Johan

--
With best wishes
Dmitry